Modeling gate emissions: A review—Part I

Results of a Monte Carlo study of carrier multiplication in silicon bipolar and field-effect transistors and of electron injection into silicon dioxide are presented. Qualitative and, in most cases, quantitative agreement is obtained only by accounting for the correct band structure, all relevant scattering processes (phonons, Coulomb, impact ionization), and the highly nonlocal properties of electron transport in small silicon devices. In addition, it is shown that quantization effects in inversion layers cause a shift of the threshold energy for impact ionization which is very significant for the calculation of the substrate current in field-effect transistors. Conservation of parallel momentum, image-force corrections, dynamic screening of the interparticle Coulomb interaction, and improvements to the WKB approximation are necessary to treat correctly the injection of electrons from silicon into silicon dioxide. The validity of models-analytic or Monte Carlo-which treat hot-electron transport with oversimplified physical approximations is argued against. In a few words, there is no shortcut. 0 I995 Ametican Institute of Physics.

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A non-defect precursor gate oxide breakdown model

Cheung

2023

Journal of Applied Physics

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Understanding defect creation is central to efforts to comprehend gate dielectric breakdown in metal-oxide-semiconductor-field-effect-transistors (MOSFETs). While gate dielectrics other than SiO2 are now popular, models developed for SiO2 breakdown are used for these dielectrics too. Considering that the Si–O bond is very strong, modeling efforts have focused in ways to weaken it so that defect creation (bond-breaking) is commensurate with experimental observations. So far, bond-breaking models rely on defect-precursors to make the energetics manageable. Here, it is argued that the success of the percolation model for gate oxide breakdown precludes the role of defect precursors in gate oxide breakdown. It is proposed that defect creation involves “normal” Si–O bonds. This new model relies on the fact that hole transport in SiO2 is in the form of a small polaron—meaning that it creates a transient local distortion as it travels. It is this transient distortion that enables normal Si–O bonds to be weakened (albeit transiently) enough that breaking the bonds at a rate commensurate with measurements becomes possible without the help of the externally applied field.

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Modeling gate emissions: A review—Part I

Cited by 4 publications

References 16 publications

Thin Gate-oxide Wear-out and Breakdown

Thin Gate-oxide Wear-out and Breakdown

Understanding hot-electron transport in silicon devices: Is there a shortcut?

A non-defect precursor gate oxide breakdown model

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